/*

* Copyright 2014-2022 The GmSSL Project. All Rights Reserved.

*

* Licensed under the Apache License, Version 2.0 (the License); you may

* not use this file except in compliance with the License.

*

* http://www.apache.org/licenses/LICENSE-2.0

*/

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <stdlib.h>

#include <sys/stat.h>

#include <gmssl/x509.h>

#include <gmssl/cms.h>

static const char *options = "-key file -pass str -cert file -in file [-out file]";

int cmsdecrypt_main(int argc, char **argv)

{

int ret = 1;

char *prog = argv[0];

char *keyfile = NULL;

char *pass = NULL;

char *certfile = NULL;

char *infile = NULL;

char *outfile = NULL;

FILE *keyfp = NULL;

FILE *certfp = NULL;

FILE *infp = NULL;

FILE *outfp = stdout;

uint8_t cert[1024];

size_t certlen;

struct stat st;

uint8_t *cms = NULL;

size_t cmslen, cms_maxlen;

SM2_KEY key;

int content_type;

uint8_t *content = NULL;

size_t content_len;

const uint8_t *rcpt_infos;

size_t rcpt_infos_len;

const uint8_t *shared_info1;

const uint8_t *shared_info2;

size_t shared_info1_len, shared_info2_len;

argc--;

argv++;

if (argc < 1) {

fprintf(stderr, "usage: %s %s\n", prog, options);

return 1;

}

while (argc > 1) {

if (!strcmp(*argv, "-help")) {

printf("usage: %s %s\n", prog, options);

ret = 0;

goto end;

} else if (!strcmp(*argv, "-key")) {

if (--argc < 1) goto bad;

keyfile = *(++argv);

if (!(keyfp = fopen(keyfile, "r"))) {

fprintf(stderr, "%s: open '%s' failure : %s\n", prog, keyfile, strerror(errno));

goto end;

}

} else if (!strcmp(*argv, "-pass")) {

if (--argc < 1) goto bad;

pass = *(++argv);

} else if (!strcmp(*argv, "-cert")) {

if (--argc < 1) goto bad;

certfile = *(++argv);

if (!(certfp = fopen(certfile, "r"))) {

fprintf(stderr, "%s: open '%s' failure : %s\n", prog, certfile, strerror(errno));

goto end;

}

} else if (!strcmp(*argv, "-in")) {

if (--argc < 1) goto bad;

infile = *(++argv);

if (!(infp = fopen(infile, "r"))) {

fprintf(stderr, "%s: open '%s' failure : %s\n", prog, infile, strerror(errno));

goto end;

}

} else if (!strcmp(*argv, "-out")) {

if (--argc < 1) goto bad;

outfile = *(++argv);

if (!(outfp = fopen(outfile, "w"))) {

fprintf(stderr, "%s: open '%s' failure : %s\n", prog, outfile, strerror(errno));

goto end;

}

} else {

fprintf(stderr, "%s: illegal option '%s'\n", prog, *argv);

goto end;

bad:

fprintf(stderr, "%s: '%s' option value missing\n", prog, *argv);

goto end;

}

argc--;

argv++;

}

if (!keyfile) {

fprintf(stderr, "%s: '-key' option required\n", prog);

goto end;

}

if (!pass) {

fprintf(stderr, "%s: '-pass' option required\n", prog);

goto end;

}

if (!certfile) {

fprintf(stderr, "%s: '-cert' option required\n", prog);

goto end;

}

if (!infile) {

fprintf(stderr, "%s: '-in' option required\n", prog);

goto end;

}

if (sm2_private_key_info_decrypt_from_pem(&key, pass, keyfp) != 1) {

fprintf(stderr, "%s: private key decryption failure\n", prog);

goto end;

}

if (x509_cert_from_pem(cert, &certlen, sizeof(cert), certfp) != 1) {

fprintf(stderr, "%s: load certificate failure\n", prog);

goto end;

}

fstat(fileno(infp), &st);

cms_maxlen = (st.st_size * 3)/4 + 1;

if (!(cms = malloc(cms_maxlen))) {

fprintf(stderr, "%s: malloc failure\n", prog);

goto end;

}

if (cms_from_pem(cms, &cmslen, cms_maxlen, infp) != 1) {

fprintf(stderr, "%s: read CMS failure\n", prog);

goto end;

}

if (!(content = malloc(cmslen))) {

fprintf(stderr, "%s: malloc failure\n", prog);

goto end;

}

if (cms_deenvelop(cms, cmslen,

&key, cert, certlen,

&content_type, content, &content_len,

&rcpt_infos, &rcpt_infos_len,

&shared_info1, &shared_info1_len,

&shared_info2, &shared_info2_len) != 1) {

fprintf(stderr, "%s: decryption failure\n", prog);

goto end;

}

if (content_type != OID_cms_data) {

fprintf(stderr, "%s: invalid CMS content type: %s\n", prog, cms_content_type_name(content_type));

goto end;

}

if (fwrite(content, 1, content_len, outfp) != content_len) {

fprintf(stderr, "%s: output failure : %s\n", prog, strerror(errno));

goto end;

}

ret = 0;

end:

if (infile && infp) fclose(infp);

if (outfile && outfp) fclose(outfp);

if (keyfile && keyfp) fclose(keyfp);

if (cms) free(cms);

if (content) free(content);

return ret;

}